package com.gongyi.demo02;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.concurrent.*;

//线程创建方式三：实现callable接口

/**
 * callable好处：
 * 1.可以定义返回值
 * 2.可以抛出异常
 */
public class TestCallable implements Callable<Boolean> {
    private String url;//网络图片地址
    private String name;//保存的文件名

    public TestCallable(String url, String name) {
        this.url = url;
        this.name = name;
    }

    //下载图片线程的执行体
    @Override
    public Boolean call() {
        WebDownloader webDownloader = new WebDownloader();
        webDownloader.downloader(url, name);
        System.out.println("下载了文件名为：" + name);
        return true;

    }

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        TestCallable t1 = new TestCallable("https://s.qunarzz.com/f_cms/2021/1638865973476_447461838.png", "qunar.png");
        TestCallable t2 = new TestCallable("https://imgs.qunarzz.com/vs_ceph_vcimg/5be2601d1f921f166646b817459a2727.jpeg", "1.jpeg");
        TestCallable t3 = new TestCallable("https://imgs.qunarzz.com/vs_ceph_vcimg/280673be5655fc91ce24ba605c62fe07.jpeg", "2.jpeg");

        //创建执行服务
        ExecutorService ser = Executors.newFixedThreadPool(3);

        //提交执行
        Future<Boolean> r1 = ser.submit(t1);
        Future<Boolean> r2 = ser.submit(t2);
        Future<Boolean> r3 = ser.submit(t3);

        //获取结果
        Boolean rs1 = r1.get();
        Boolean rs2 = r2.get();
        Boolean rs3 = r3.get();

        System.out.println(rs1);
        System.out.println(rs2);
        System.out.println(rs3);

        //关闭服务
        ser.shutdown();


    }


}

//下载器
class WebDownloader {
    //下载方法
    public void downloader(String url, String name) {
        try {
            FileUtils.copyURLToFile(new URL(url), new File(name));//看源码
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("IO异常，downloader方法出现异常");
        }
    }
}
